#define _CRT_SECURE_NO_WARNINGS 1
class Solution {
public:
    ListNode* addTwoNumbers(ListNode* l1, ListNode* l2)
    {
        ListNode* cur1 = l1, * cur2 = l2;
        ListNode* newhead = new ListNode(0);
        ListNode* prev = newhead;
        int t = 0;
        while (cur1 || cur2 || t)
        {
            if (cur1)
            {
                t += cur1->val;
                cur1 = cur1->next;
            }
            if (cur2)
            {
                t += cur2->val;
                cur2 = cur2->next;
            }

            prev->next = new ListNode(t % 10);
            prev = prev->next;
            t /= 10;
        }

        prev = newhead->next;
        delete newhead;

        return prev;
    }
};